How to Read and Understand Hot Tub Water Test Strips

Written by: Zach Riggs



Time to read 4 min

Maintaining your hot tub's water quality isn't just about ensuring a pleasant soak; it's a vital practice to keep the water safe and hygienic. Regular testing using hot tub test strips is essential to this maintenance, making it easy to ascertain if adjustments to your hot tub chemicals are needed. This comprehensive guide will walk you through the use of test strips effectively and explain the significance of each element they measure.


Hot tub test strips are an invaluable tool in your spa maintenance kit. They are designed to quickly indicate whether the chemical composition of your hot tub water is within the desired range. These strips measure various elements, including Total Alkalinity (TA), pH levels, and sanitizer levels, which could be either chlorine or bromine, depending on your hot tub setup. 

The Importance of Regular Testing

Regular testing is not just a recommendation; it's necessary for maintaining your hot tub's health and longevity. Test strips allow you to monitor the chemical balance of your water, ensuring it remains safe for use and preventing long-term damage to your hot tub components. This routine check can help avoid skin irritation, cloudy water, and scale buildup. 

How Do Test Strips Work?

Hot tub test strips are an easy and efficient way to test the water quality in your hot tub. Each strip has reagents that react with specific chemicals in the water, causing a color change that indicates the current levels of those chemicals. By comparing the colors on the strip to the color chart on the bottle, you can quickly determine if your water is within the recommended range for pH, total alkalinity, chlorine, or bromine levels.


Using hot tub test strips regularly can help you maintain a safe and healthy hot tub. By monitoring the levels of chemicals in your water, you can prevent issues like skin irritation, cloudy water, and even illness. It's a simple and affordable way to ensure your hot tub is always ready. 

Step-by-Step Guide to Using Hot Tub Test Strips



Before using a test strip, ensure all hot tub jets and pumps are off to stabilize the water.

Submerging the Strip

Dip the test strip into the water, submerging it to your wrist. Swirl it around three times to capture a representative sample of the water.

Removing and Shaking

After a few seconds, remove the strip from the water and give it a quick shake to remove excess water, which could skew the readings.

Comparing Colors

Hold the strip to the color chart on its bottle. For the most accurate reading, do this within 30 seconds of removing it from the water.

Reading the Results

Start by checking the Total Alkalinity. Check the pH level and other elements with the same strip if the TA is within the desired range. If adjustments to TA are necessary, make them and then retest with a new strip.

Sanitizer Levels

Finally, check the levels of your chosen sanitizer, whether it's chlorine or bromine. This is crucial for keeping your hot tub water safe and free from harmful microorganisms.

Understanding the Different Measurements

  • Total Alkalinity (TA): TA acts as a buffer for the pH level, preventing sudden changes. The ideal range is between 125-155 ppm. Unbalanced TA can lead to fluctuating pH levels, affecting water quality and comfort.
  • pH Levels: The pH level indicates how acidic or alkaline your hot tub water is. A balanced pH (between 7.2 and 7.6) is critical for comfort and ensuring that your sanitizers work effectively.
  • Total Hardness (TH): This measures the calcium content in your water. Ideal levels should be between 175 and 250 PPM. Too much hardness can lead to scale formation, while too little can cause the water to become corrosive.
  • Sanitizer Levels: Sanitizers like chlorine or bromine keep your hot tub water free from bacteria and other pathogens. Chlorine levels should be between 3 and 5mg/l, and bromine levels should be between 4 and 6mg/l.

Choosing the Right Test Strips

Selecting the correct test strips is crucial. If using a chlorine-based sanitizer, ensure your strips can measure chlorine levels. Similarly, choose strips designed to measure bromine levels for bromine sanitizers. Some multi-purpose strips, TA, pH, and TH, can measure both. 

Frequency of Testing

Test your hot tub's pH and sanitizer levels daily for optimal water quality. Total Alkalinity and Total Hardness should be checked once a week. This regular testing helps in the early detection of any imbalance, allowing for prompt adjustments.


Storing Your Test Strips

Proper storage of test strips is essential for ensuring their accuracy. Please keep them in a cool, dry place, and make sure your hands are dry each time you reach for a strip. Permanently fasten the lid tightly to prevent moisture from entering the bottle.


Troubleshooting Common Issues

Recheck your chemical levels using the test strips if you encounter problems like cloudy water or unusual chemical smells. Often, these issues are due to an imbalance in pH, TA, or sanitizer levels. Adjusting these levels accordingly can resolve most common hot tub water quality problems. 

Mastering hot tub test strips is a crucial aspect of maintaining your spa. While the process might seem daunting initially, it becomes a quick and routine task with practice. Regular testing and adjustment of your hot tub chemicals ensure a safe, enjoyable, hygienic, desirable tub experience.


By following these guidelines and understanding the importance of each chemical level, you can ensure your hot tub remains a source of relaxation and enjoyment for years to come. Remember, maintaining water quality is not just about adding chemicals; it's about understanding their interactions and achieving the perfect balance for your hot tub environment.